Can you explain Drug Harm Reduction? There are differing opinions on the morality of distributing condoms and syringes. Why have you chosen this method for Uzbekistan?Drug Harm Reduction focuses on introducing immediate precautions and safety measures with a view to eventual behaviour change, which is why we distribute condoms and syringes to injecting drug users, homosexuals and commercial sex workers. Drug Demand Reduction also focuses on peer-to-peer education and on raising public awareness regarding HIV/AIDS issues over a longer period.
The morality of Harm Reduction programs has been under debate for some time at the international level – it has been argued that syringe/needle exchange and condom distribution simply encourage drug use and high-risk behaviour. However as a Christian organisation, we believe that God created all people, loves and values each human life immeasurably, and instructs us to do all we can to preserve and enhance life. Therefore in high-risk situations we encourage safe practice first through condom and clean syringe use as a means to preserve and protect life and reduce the transmission of the HIV virus. At the same time we promote long-term behaviour change through counseling and education. (Source)
Recent virus transport models consider non-static pressures across the latex film, which are more realistic of the use of condoms in coital situations.
Key words: virus transmission, computational fluid dynamics, barrier evaluation, transport modeling. Scientists often perform tests on the effectiveness of synthetic barriers (gloves, condoms, instrument sheaths, etc.) to virus transmission under conditions that do not reflect actual use. For example, static test conditions are typically employed while, in reality, considerable motion is associated with use of the barrier. In order to extend laboratory results to more realistic conditions, OST has developed a mathematical model for simulating virus transport through synthetic barriers. The model was recently used to estimate the amount of virus that would be transmitted through a defect in a condom during coitus.Input into the model was the pressure difference across the condom surface, which was previously measured by OST scientists during coital simulations. The pressure waveform was periodic (a period of 2 seconds was used), with a maximum pressure difference across of approximately 60 millimeters of mercury and a minimum of approximately minus-20 millimeters of mercury. Defects of various cross-sectional shapes were considered, from circles to wide ellipses. The rate constants characterizing the interaction force between the virus and latex were obtained from previous calibration experiments if available. Where rate-constant values were not available, upper and lower bounds were used to determine the range of virus transmission rates.Virus transport under unsteady conditions revealed several interesting differences compared to steady-state transport through a pore. The oscillatory flow through the pore, which included flow from the outside of the condom to inside during part of the cycle, gave rise to better mixing of the virus suspension in the vicinity on the pore and, consequently, more adsorption of the viruses to the inside and outside surfaces of the condom. The amount of free viruses actually transmitted through the pore was consequently reduced relative to the case of a steady driving pressure. Another interesting feature of the transport was that the quantity of viruses transmitted through the pore decreased slightly with each cycle. This presumably arises from the gradual dilution of the virus concentration near the inlet of the pore, due to diffusion of the viruses to the condom interior surface and subsequent adsorption. For small pores with diameters on the order of a micron, the viruses can diffuse a distance equal to the pore diameter in less than a second, while the period associated with the periodic motion is at least a second. Hence diffusion in the direction normal to the pore axis is an important mechanism.Calculations using a 10-micron diameter circular-cylinder pore in a latex condom revealed a transmission rate of approximately 10 herpes viruses per cycle, assuming a saline suspending fluid and a titer inside the condom of 1 million viruses/ml. For a suspension of HIV, the flux would be on the order of 1 virus per cycle due to the lower titers of HIV. For hepatitis B, the titers can be as high as 10 billion/ml, and the number of viruses transmitted per cycle could be in the thousands.OST scientists are presently applying the virus-transport model to other realistic-use scenarios, such as a gloved-hand gripping an instrument during a surgical procedure. In this simulation the brief but intense pressure on the barrier surface produces a surge in virus suspension (e.g., HIV suspended in blood) through any tears present in the glove.
Recall the unit conversions above: a 10 micron hole is 0.01 millimeters—a hole much too small to be seen with the naked eye. And yet 10 microns is 10,000 nm. Recall further that an HIV virus is 110 to 146 nm. Such a hole allows for the passage of Herpes, hepatitis, and HIV viruses. There is sufficient evidence here that manufacturing defects and other “large” holes exist and can be virus transmission passages. If surgeons are double-gloving that has to say something.
Condoms, like all manufactured products, have inherent defects. Furthermore, they age, degrade in ozone or with particularly high and low temperatures. They have a propensity to fail even with respect to prevention of pregnancy—hence the recommendations to use condoms with spermicide for the prevention of pregnancy. Condom breakage and slippage don’t always result in pregnancy—recall that a woman is only fertile for about 5 days out of a month—but HIV and other diseases can be transmitted at any time.
And in the case of viruses, it is not just slippage and breakage failures but also the presence of holes in the order of a few microns across—too small to be seen but plenty big enough for viruses. If you don’t believe Cardinal Trujillo, perhaps you’ll believe the Dr. Helen Singer Kaplan, founder of the Human Sexuality Program at the New York Weill Cornell Medical Center, Cornell University, published in The Real Truth about Women and AIDS. Simon & Schuster, 1987. (Source)